Lead System with Boost Battery - 2009 E4

Starting a new topic to document outcome with Lead Boost battery on all lead system… Any words of wisdom before I start… Dave has been a great help so far…

I can’t wait. :slightly_smiling_face:

I have disconnected the batteries from the controller and placed an additional lead battery in between the controller and b+ form the batteries… Total voltage was near 82 v. Test drove car and noticed slightly more torque however an increase in speed of 1-2 mph… I have Dave’s MM installed at its default setting, controller is defaulted. I was expecting a better increase in top speed, however batteries were about 80%. I am charging the car and the add on battery separately and will retest. I am a little disappointed with initial results.

Factory Motor/Controller

If you haven’t done the field weakening yet, don’t get too discouraged. I removed my speed limiter and didn’t see a big jump in speed until I weakened the field.

That is disappointing, but not totally unexpected.
Stock voltage can be 86v after a full charge. And unlike lithium you are gaining weight.
It was worth a shot to get a performance boost for $100.
We run up to 98v with lithium, that’s almost two more batteries worth of voltage.

I will try with two batteries full charged Monday.